#include <Carbon/Carbon.h> 
#include <OpenGL/OpenGL.h>


int main() 
{ 
    char val = 0;
    char *fb = (char *)CGDisplayAddressForPosition(kCGDirectMainDisplay, 0, 0);
    int rowbytes = CGDisplayBytesPerRow(kCGDirectMainDisplay);
    printf("hereA\n");
    //CGDisplayCaptureWithOptions(kCGDirectMainDisplay, kCGCaptureNoFill);
    CGDisplayCapture(kCGDirectMainDisplay);
    for (int j=0;j<50;j++)
    {
        for (int i=0;i<rowbytes;i++) 
        { 
            *fb++ = val++; 
            //val = *fb++;
        }
    }
    CGDisplayRelease(kCGDirectMainDisplay);
    printf("hereB\n");
    return 0;
}